As London grew, the city spread in all directions. The rich used lands to the west, above the smell of sewerage and life. The north largely remained as villages, while the south was under water for mush of the year. So, industry along with it s poorer workers spread to the east along the north bank of the Thames. Here, the major dockyards multiplied with compacted housing for the workers.

The East End of London is the historic core of east London, traditionally consisting of areas close to the City of London on the western, Middlesex side of the River Lea (in the former Tower Division), although the term "East End" is often used more loosely. Neither east London nor the East End of London have precise, formal definitions. The Eastern (E) Postal District is a different subset of East London; and there is also an "East" sub-region used by the Greater London Authority for planning policy reporting purposes.

The East End, the old core of modern East London, began with the medieval growth of London beyond the city walls, along the Roman roads leading from Bishopsgate and Aldgate, and also along the river.

Growth was much slower in the east, and the modest extensions there were separated from the much larger suburbs in the west by the marshy open area of Moorfields adjacent to the wall on the north side, which discouraged development in that direction. Urbanisation accelerated in the 16th century and the area that would later become known as the East End began to take shape.

The first known written record of the East End as a distinct entity, as opposed to its component parts, comes from John Strype's 1720 'Survey of London', where he describes London as consisting of four parts: the City of London, Westminster, Southwark, and That Part beyond the Tower.

The relevance of Strype's reference to the Tower was more than geographical. The East End was the urbanised part of an area called the Tower Division, which had owed military service to the Tower of London since time immemorial. Later, as London grew further, the fully urbanised Tower Division became a byword for wider East London, before East London grew further still, east of the Lea and into Essex.

The westernmost component of the Tower Division was the ancient parish of Shoreditch, which would become fully urbanised as part of the East End/East London. Shoreditch's boundary with the parish of St Luke's (which, like its predecessor St Giles-without-Cripplegate served the Finsbury area) ran through the Moorfields countryside. These boundaries remained consistent after urbanisation and so might be said to delineate east and north London. The boundary line, with very slight modifications, has also become the boundary between the modern London Boroughs of Hackney and Islington.

Moorfields remained largely open until 1812, and the longstanding presence of that open space separating the emerging East End from the western urban expansion of London must have helped shape the varying economic character of the two parts and perceptions of their distinct identity.

Areas further east developed in the Victorian and Edwardian eras after the expansion of the railways in the 19th century. Development of suburban houses for private sale was later matched by the provision of large-scale social housing at Becontree in the 1920s and Harold Hill after the Second World War. However, the urban footprint was constrained in 1878 by the protection of Epping Forest and later the implementation of the Metropolitan Green Belt. The density of development increased during the interwar period, and new industries developed, such as Ford at Dagenham. In Tower Hamlets, the population peaked in 1891 and growth was restricted to the outer boroughs. By 1971, the population had peaked in every borough and the population was declining throughout the entire area. By the time of the 2011 UK Census, this had reversed and every borough had undergone some growth in population.